Magnetic cobalt ferrite biochar composite as peroxymonosulfate activator for removal of lomefloxacin hydrochloride

Abstract

• MBC/CoFe 2 O 4 was synthesized as a catalyst for the degradation of LFH by PMS. • MBC/CoFe 2 O 4 had good magnetic properties performance and superior reusability. • SO 4 ∙- , ∙OH, ∙O 2 – and 1 O 2 participated in the reaction in the constructed system. • The possible pathways and mechanisms of the LFH degradation were deduced. In this work, cost-effective peroxymonosulfate (PMS) was used as oxidants and magnetic cobalt ferrite biochar composite was used as catalyst to remove lomefloxacin hydrochloride (LFH), a new pollutant in water. PMS activation by CoFe 2 O 4 was promoted by compositing with biochar. The MBC/CoFe 2 O 4 /PMS system degraded 86.9% of LFH in 20 min. MBC/CoFe 2 O 4 measured by vibrating sample magnetometer (VSM) had good magnetic properties and was convenient for separation and recovery. Furthermore, the main active oxide species were determined by EPR measurement. The catalytic mechanism of MBC/CoFe 2 O 4 /PMS system was attributed to the generation of sulfate radicals (SO 4 ∙- ), hydroxyl radicals (∙OH), singlet oxygen ( 1 O 2 ) and superoxide radicals (∙O 2 – ) additionally, of which SO 4 ∙- played the leading role. Moreover, a possible degradation pathway of LFH was proposed. MBC/CoFe 2 O 4 /PMS system still had 85.7% LFH removal efficiency after five times of reuse. Thence, the MBC/CoFe 2 O 4 composite material might be a candidate for removing difficult pollutants in environmental remediation.